Shouto is a chronic shut-in, not leaving his room for years. His parents hire an agency that’s supposed to help people with this condition, called “Shut-less”. This leads to Shouto getting a visit from Sayane, a tall beautiful woman employed by the agency. What nobody expects is for Sayane to dominate Shouto, training him to become her masochistic fuck boy. In the process, he’s becoming more and more dependent on her. Is Shouto only trading one cage for another and will he obtain happiness in the end?